A pectin-honey hydrogel prevents postoperative intraperitoneal adhesions in a rat model

Polysaccharide-based hydrogels for medical devices, implants and tissue engineering: A review

Hydrogels are highly biocompatible biomaterials composed of crosslinked three-dimensional networks of hydrophilic polymers. Owing to their natural origin, polysaccharide-based hydrogels (PBHs) possess low toxicity, high biocompatibility and demonstrate in vivo biodegradability, making them great candidates for use in various biomedical devices, implants, and tissue engineering. In addition, many polysaccharides also show additional biological activities such as antimicrobial, anticoagulant, antioxidant, immunomodulatory, hemostatic, and anti-inflammatory, which can provide additional therapeutic benefits. The porous nature of PBHs allows for the immobilization of antibodies, aptamers, enzymes and other molecules on their surface, or within their matrix, potentiating their use in biosensor devices. Specific polysaccharides can be used to produce transparent hydrogels, which have been used widely to fabricate ocular implants. The ability of PBHs to encapsulate drugs and other actives has been utilized for making neural implants and coatings for cardiovascular devices (stents, pacemakers and venous catheters) and urinary catheters. Their high water-absorption capacity has been exploited to make superabsorbent diapers and sanitary napkins. The barrier property and mechanical strength of PBHs has been used to develop gels and films as anti-adhesive formulations for the prevention of post-operative adhesion. Finally, by virtue of their ability to mimic various body tissues, they have been explored as scaffolds and bio-inks for tissue engineering of a wide variety of organs. These applications have been described in detail, in this review.

The Effects of Pectin-Honey Hydrogel in a Contaminated Chronic Hernia Model in Rats

Incisional hernia is a frequent complication after abdominal surgery. A previous study on rats evaluated the use of a Pectin-Honey Hydrogel (PHH)-coated polypropylene (PP) mesh for the healing of acute hernias. However, there are no studies investigating the use of PHH in association with PP mesh in chronic contaminated hernia. The aims of this study are to assess the effectiveness of PHH in promoting abdominal hernia repaired with PP mesh and in counteracting infection. Twenty Sprague Dawley male rats were enrolled and a full thickness defect was made in the abdominal wall. The defect was repaired after 28 days using a PP mesh, and a culture medium (Tryptone Soy Broth, Oxoid) was spread onto the mesh to contaminate wounds in both groups. The rats were randomly assigned to a treated or untreated group. In the treated group, a PHH was applied on the mesh before skin closure. At euthanasia-14 days after surgery-macroscopical, microbiological and histopathological evaluations were performed, with a score attributed for signs of inflammation. An immunohistochemical investigation against COX-2 was also performed. Adhesions were more severe (p = 0.0014) and extended (p = 0.0021) in the untreated group. Bacteriological results were not significantly different between groups. Both groups showed moderate to severe values (score > 2) in terms of reparative and inflammatory reactions at histopathological levels. The use of PHH in association with PP mesh could reduce adhesion formation, extension and severity compared to PP mesh alone. No differences in terms of wound healing, contamination and grade of inflammation were reported between groups.

The Therapeutic Potential of Targeting Key Signaling Pathways as a Novel Approach to Ameliorating Post-Surgical Adhesions

BACKGROUND

Peritoneal adhesions (PA) are a common complication of abdominal operations. A growing body of evidence shows that inhibition of inflammation and fibrosis at sites of peritoneal damaging could prevent the development of intra-abdominal adhesions.

METHODS

A search of PubMed, Medline, CINAHL and Embase databases was performed using the keywords 'postsurgical adhesion', 'post-operative adhesion', 'peritoneal adhesion', 'surgery-induced adhesion' and 'abdominal adhesion'. Studies detailing the use of pharmacological and non-pharmacological agents for peritoneal adhesion prevention were identified, and their bibliographies were thoroughly reviewed to identify further related articles.

RESULTS

Several signaling pathways, such as tumor necrosis factor-alpha, tissue plasminogen activator, and type 1 plasminogen activator inhibitor, macrophages, fibroblasts, and mesothelial cells play a key part in the development of plasminogen activator. Several therapeutic approaches based on anti-PA drug barriers and traditional herbal medicines have been developed to prevent and treat adhesion formation. In recent years, the most promising method to prevent PA is treatment using biomaterial-based barriers.

CONCLUSION

In this review, we provide an overview of the pathophysiology of adhesion formation and various agents targeting different pathways, including chemical agents, herbal agents, physical barriers, and clinical trials concerning this matter.

Bioactivity and Chemical Characterization of Sudanese Bee Honey: Crude Acacia and Its Organic Extracts

Honey has recently been rediscovered as an antibacterial and wound-healing natural product. The medicinal properties of honey originate from the floral source used by bees. The objective of the current study was to evaluate the antimicrobial activity of Sudanese crude acacia bee honey and its solvent extracts regarding its biological activity and chemical characterization. To verify the nature of the antibacterial agent(s) of honey, sample (A) Sudanese crude unprocessed acacia bee honey obtained from west of Sudan (Nyala) during October 2019 was tested in vitro for antibacterial activity against 10 standard microorganisms Enterobacter aerogenes: ATCC: 13048, Enterococcus faecalis: ATCC: 29212, Escherichia coli: ATCC: 25922, Klebsiella pneumoniae: ATCC: 700603, Pseudomonas aeruginosa: ATCC: 27853, Serratia marcescens: ATCC: 8100, Staphylococcus aureus: ATCC: 29213, Staphylococcus epidermidis: ATCC: 12228, Staphylococcus Methicillin Sensitive MSSA: ATCC: 29213, and Staphylococcus Methicillin-Resistant MRSA: ATCC: 23591. Extraction of honey sample was carried out by petroleum ether followed by ethyl acetate using liquid/liquid extraction technique, using separating funnels. All organic extracts in addition to their aqueous residue were tested in vitro for antibacterial activity against the10 standard microorganisms. Ethyl acetate extract was subjected to gas chromatography-mass spectrometer (GC-MS) for chemical characterization. Sudanese crude unprocessed acacia honey showed inhibitory effects against the 10 standard microorganisms. Petroleum ether extract showed no antibacterial activity against the tested organisms, while its water residue exhibited remarkable activity. The ethyl acetate extract exhibited strong antibacterial activity against the tested organisms, while its aqueous residue showed no activity. Ethyl acetate extract subjected to gas chromatography-mass spectrometer (GC-MS) showed twenty-one chemical constituents. The GC-MS showed twenty-one chemical compounds, and phenolic compound was the highest concentration. Ethyl acetate extract exhibited strong antibacterial activity which can be formulated as topical dressing for wounds and burns. The usage of honey in a professional context should be taken into consideration while treating burns and wounds.

Recent advances on biomedical applications of pectin-containing biomaterials

There is a growing demand for biomaterials developing with novel properties for biomedical applications hence, hydrogels with 3D crosslinked polymeric structures obtained from natural polymers have been deeply inspected in this field. Pectin a unique biopolymer found in the cell walls of fruits and vegetables is extensively used in the pharmaceutical, food, and textile industries due to its ability to form a thick gel-like solution. Considering biocompatibility, biodegradability, easy gelling capability, and facile manipulation of pectin-based biomaterials; they have been thoroughly investigated for various potential biomedical applications including drug delivery, wound healing, tissue engineering, creation of implantable devices, and skin-care products.

Barrier materials for prevention of surgical adhesions: systematic review

BACKGROUND

Postoperative surgical adhesions constitute a major health burden internationally. A wide range of materials have been evaluated, but despite constructive efforts and the obvious necessity, there remains no specific barrier widely utilized to prevent postoperative adhesion formation. The aim of this study was to highlight and characterize materials used for prevention of postoperative surgical adhesions in both animal and human studies.

METHODS

A systematic review was performed of all original research articles presenting data related to the prevention of postoperative adhesions using a barrier agent. All available observational studies and randomized trials using animal models or human participants were included, with no restrictions related to type of surgery. PubMed and Embase databases were searched using key terms from inception to August 2019. Standardized data collection forms were used to extract details for each study and assess desirable characteristics of each barrier and success in animal and/or human studies.

RESULTS

A total of 185 articles were identified for inclusion in the review, with a total of 67 unique adhesion barrier agents (37 natural and 30 synthetic materials). Desirable barrier characteristics of an ideal barrier were identified on review of the literature. Ten barriers achieved the primary outcome of reducing the incidence of postoperative adhesions in animal studies followed with positive outputs in human participants. A further 48 materials had successful results from animal studies, but with no human study performed to date.

DISCUSSION

Multiple barriers showed promise in animal studies, with several progressing to success, and fulfilment of desirable qualities, in human trials. No barrier is currently utilized commonly worldwide, but potential barriers have been identified to reduce the burden of postoperative adhesions and associated sequelae.

A combination of hybrid polydopamine-human keratinocyte growth factor nanoparticles and sodium hyaluronate for the efficient prevention of postoperative abdominal adhesion formation

Postoperative abdominal adhesion (PAA) is one of the more universal complications of abdominal surgery with a frequent incidence. Currently available keratinocyte growth factor (KGF)-based glues for the prevention of adhesions remain a great bottleneck since their long-term biological activity in vivo is insufficient. In this study, we fabricated hybrid polydopamine (PDA)-KGF nanoparticles (PDA-KGF NPs) by using an in situ self-assembly and polymerization method. The physicochemical properties of the PDA-KGF nanoparticles were systematically characterized. The effect of preventing PAA in rats was evaluated by using hybrid PDA-KGF NPs combined with hyaluronate (Ha). The expression levels of inflammatory factors and the degree of inflammatory cell infiltration in the injured peritoneum were evaluated by enzyme-linked immunosorbent assays and hematoxylin-eosin staining, respectively. The levels of phospho-Src expression were revealed by Western blotting. The degree of fibrosis and the density of deposited collagen fibers were measured with real-time reverse-transcription polymerase chain reaction and picrosirius red staining. The results indicated that the PDA-KGF NPs combined with Ha greatly prevented the incidence of abdominal adhesion s and promoted the repair of mesothelial cells in injured peritoneum. More importantly, the PDA-KGF NPs combined with Ha obviously reduced collagen deposition and fibrosis and inhibited the inflammatory response. Our results suggest that PDA-KGF NPs combined with Ha are promising barrier-like biomaterials for the effective prevention of postoperative tissue adhesion. STATEMENT OF SIGNIFICANCE: Postoperative abdominal adhesion (PAA) as an inevitable postoperative complication affected the quality of life of patients. Currently available methods for preventing adhesions mainly employ degradable biomaterials. Previous research demonstrated that a hybrid keratinocyte growth factor (KGF)-sodium hyaluronate (Ha) gel could prevent the formation of PAAs. However, its clinical outcomes are not satisfactory since their bioactivity in vivo is too short. In this article, we fabricated hybrid polydopamine (PDA)-KGF nanoparticles (PDA-KGF NPs), which extend KGF bioactivity, effectively prevent PAA. Moreover, PDA-KGF NPs could remarkably reduce both collagen deposition and fibrosis, inhibit the inflammatory response, and promote mesothelial regeneration. Overall, the PDA-KGF NPs combined with Ha exhibit efficient antiadhesion properties, may provide a promising clinical protocol for the prevention of PAA.

In Vivo Evaluation of a Pectin-Honey Hydrogel Coating on Polypropylene Mesh in a Rat Model of Acute Hernia

Investigations about ventral hernia repair are focused on improving the quality, resistance, and biocompatibility of mesh. This study compared plain polypropylene mesh with a pectin-honey hydrogel-coated polypropylene mesh in an acute hernia model in rats. Forty Wistar rats, randomly assigned to two groups, were submitted to laparotomy, and a 1 cm × 2 cm fascial defect was created, centered on the midline. Uncoated (group C) or coated mesh (group T) was inserted in an inlay fashion to repair the defect. After 30 days, the rats were euthanized, and the presence of adhesions to the mesh was macroscopically evaluated. Histology and measurement of COX-2 as tissue inflammation markers were used to assess fascia tissue healing. Grades of adhesion were not different between groups. Histological score and COX-2 expression were not significantly different between groups, except for the higher inflammatory response demonstrated in group T. The pectin-hydrogel coated mesh could not reduce adhesion formation compared to uncoated polypropylene mesh but improved peritoneal regeneration and tissue healing.

Therapeutic potential of active components of saffron in post-surgical adhesion band formation

BACKGROUND

Abdominal adhesions are common and often develop after abdominal surgery. There are currently no useful targeted pharmacotherapies for adhesive disease. Saffron and its active constituents, Crocin and Crocetin, are wildly used in traditional medicine for alleviating the severity of inflammatory or malignant disease.

PURPOSE

The aim of this study was to investigate the therapeutic potential of the pharmacological active component of saffron in attenuating the formation of post-operative adhesion bands using different administration methods in a murine model.

MATERIAL METHOD

saffron extract (100 mg/kg), Crocin (100 mg/kg), and Crocetin (100 mg/kg) were administered intraperitoneally and by gavage in various groups of male Wistar rat post-surgery. Also three groups were first treated intra-peritoneally by saffron extract, Crocin, and Crocetin (100 mg/kg) for 10 days and then had surgery. At the end of the experiments, animals sacrificed for biological assessment.

RESULT

A hydro-alcoholic extract of saffron and crocin but not crocetin potently reduced the adhesion band frequency in treatment and pre-treatment groups in the mice given intra-peritoneal (i.p) injections. Following the saffron or crocin administration, histological evaluation and quantitative analysis represented less inflammatory cell infiltration and less collagen composition, compared to control group. Moreover, the oxidative stress was significantly reduced in treatment groups.

CONCLUSION

These findings suggest that a hydro-alcoholic extract of saffron or its active compound, crocin, is a potentially novel therapeutic strategy for the prevention of adhesions formation and might be used as beneficial anti-inflammatory or anti-fibrosis agents in clinical trials.

TAXONOMY

Abdominal surgeries/post-surgical adhesions.

The roles of strawberry and honey phytochemicals on human health: A possible clue on the molecular mechanisms involved in the prevention of oxidative stress and inflammation

BACKGROUND

Oxidative stress and inflammation contribute to the etiopathogenesis of several human chronic diseases, such as cancer, diabetes, cardiovascular diseases and metabolic syndrome. Besides classic stimuli, such as reactive oxidant species, endotoxins (i.e., bacteria lipopolysaccharide), cytokines or carcinogens, oxidative stress and inflammation can be triggered by a poor diet and an excess of body fat and energy intake. Strawberry and honey are common rich sources of nutrients and bioactive compounds, widely studied for their roles exerted in health maintenance and disease prevention.

PURPOSE

This review aims to summarize and update the effects of strawberry and honey against oxidative stress and inflammation, with emphasis on metabolism and on the main molecular mechanisms involved in these effects.

METHODS

A wide range of literature, published in the last 10 years, elucidating the effects of strawberry and honey in preventing oxidative stress and inflammation both in vitro (whole matrix and digested fractions) and in vivo was collected from online electronic databases (PubMed, Scopus and Web of Science) and reviewed.

RESULTS

Strawberry and honey polyphenols may potentially prevent the chronic diseases related to oxidative stress and inflammation. Several in vitro and in vivo studies reported the effects of these foods in suppressing the oxidative stress, by decreasing ROS production and oxidative biomarkers, restoring the antioxidant enzyme activities, ameliorating the mitochondrial antioxidant status and functionality, among others, and the inflammatory process, by modulating the mediators of acute and chronic inflammation essential for the onset of several human diseases. These beneficial properties are mediated in part through their ability to target multiple signaling pathways, such as p38 MAPK, AMPK, PI3K/Akt, NF-κB and Nrf2.

CONCLUSIONS

Available scientific literature show that strawberry and honey may be effective in preventing oxidative stress and inflammation. The deep evaluation of the factors that affect their metabolism as well as the assessment of the main molecular mechanisms involved are of extreme importance for the possible therapeutic and preventive benefit against the most common human diseases. However, published literature is still scarce so that deeper studies should be performed in order to evaluate the bioavailability of these food matrices and their effects after digestion.

Peritoneal adhesions: Occurrence, prevention and experimental models

Peritoneal adhesions (PA) are a postoperative syndrome with high incidence rate, which can cause chronic abdominal pain, intestinal obstruction, and female infertility. Previous studies have identified that PA are caused by a disordered feedback of blood coagulation, inflammation, and fibrinolysis. Monocytes, macrophages, fibroblasts, and mesothelial cells are involved in this process, and secreted signaling molecules, such as tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10), tissue plasminogen activator (tPA), and type 1 plasminogen activator inhibitor (PAI-1), play a key role in PA development. There have been many attempts to prevent PA formation by anti-PA drugs, barriers, and other therapeutic methods, but their effectiveness has not been widely accepted. Treatment by biomaterial-based barriers is believed to be the most promising method to prevent PA formation in recent years. In this review, the pathogenesis, treatment approaches, and animal models of PA are summarized and discussed to understand the challenges faced in the biomaterial-based anti-PA treatments.

A Critical Review and Perspective of Honey in Tissue Engineering and Clinical Wound Healing

Significance: Historically, honey has been regarded as a potent agent in bacterial inhibition and wound healing. An increased prevalence of antibiotic resistant pathogens spurred an initial resurgence in honey's clinical popularity, with it quickly finding a place in wound care and regenerative medicine. However, this renewed usage demanded a need for improved delivery and overall research of its bioactive properties. This review provides an overview of the antibacterial properties and clinical use of honey. Recent Advances: The past and present clinical use of honey is noted, focusing specifically on burns and ulcers, as these are the most common applications of the natural agent. While honey is often used without modification clinically, there are also commercially available products ranging from dressings to gels, which are discussed. Critical Issues: Despite these products growing in popularity, the need for improved delivery and a structure to support wound healing could improve the treatment method. Future Directions: Tissue engineering scaffolds can provide an alternative method of honey delivery with research focusing primarily on electrospun scaffolds, hydrogels, and cryogels. Current studies on these scaffolds are discussed with respect to their advantages and potential for future clinical work. Overall, this review provides a comprehensive overview of the properties of honey, its current use in wound healing, and the potential for future incorporation into tissue-engineered scaffolds to provide an innovative wound healing agent.

The sticky business of adhesion prevention in minimally invasive gynecologic surgery

PURPOSE OF REVIEW

The negative impact of postoperative adhesions has long been recognized, but available options for prevention remain limited. Minimally invasive surgery is associated with decreased adhesion formation due to meticulous dissection with gentile tissue handling, improved hemostasis, and limiting exposure to reactive foreign material; however, there is conflicting evidence on the clinical significance of adhesion-related disease when compared to open surgery. Laparoscopic surgery does not guarantee the prevention of adhesions because longer operative times and high insufflation pressure can promote adhesion formation. Adhesion barriers have been available since the 1980s, but uptake among surgeons remains low and there is no clear evidence that they reduce clinically significant outcomes such as chronic pain or infertility. In this article, we review the ongoing magnitude of adhesion-related complications in gynecologic surgery, currently available interventions and new research toward more effective adhesion prevention.

RECENT FINDINGS

Recent literature provides updated epidemiologic data and estimates of healthcare costs associated with adhesion-related complications. There have been important advances in our understanding of normal peritoneal healing and the pathophysiology of adhesions. Adhesion barriers continue to be tested for safety and effectiveness and new agents have shown promise in clinical studies. Finally, there are many experimental studies of new materials and pharmacologic and biologic prevention agents.

SUMMARY

There is great interest in new adhesion prevention technologies, but new agents are unlikely to be available for clinical use for many years. High-quality effectiveness and outcomes-related research is still needed.

Mechanical properties, structure, bioadhesion, and biocompatibility of pectin hydrogels

The surface structure, biocompatibility, textural, and adhesive properties of calcium hydrogels derived from 1, 2, and 4% solutions of apple pectin were examined in this study. An increase in the pectin concentration in hydrogels was shown to improve their stability toward elastic and plastic deformation. The elasticity of pectin hydrogels, measured as Young's modulus, ranged from 6 to 100 kPa. The mechanical properties of the pectin hydrogels were shown to correspond to those of soft tissues. The characterization of surface roughness in terms of the roughness profile (Ra) and the root-mean-square deviation of the roughness profile (Rq) indicated an increased roughness profile for hydrogels depending on their pectin concentration. The adhesion of AU2% and AU4% hydrogels to the serosa abdominal wall, liver, and colon was higher than that of the AU1% hydrogel. The adhesion of macrophages and the non-specific adsorption of blood plasma proteins were found to increase as the pectin concentration in the hydrogels increased. The rate of degradation of all hydrogels was higher in phosphate buffered saline (PBS) than that in DMEM and a fibroblast cell monolayer. The pectin hydrogel was also found to have a low cytotoxicity. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2572-2581, 2017.